The Flow cytometry facility has recently installed a FACSCan for use by DIR investigators; this instrument is being rented from the BEIB at NIH. In addition to its use by the DIR, we will use it to provide a theory and practical course in flow cytometry. The BD multiparameter FACS Vantage was installed this FY. It is equipped with three lasers (argon, argon/dye and krypton) which will enable it to perform 5 visible colors, and combined visible/UV analyses and sorting. It also has the four color-single laser option for performing 4 color analyses from the argon laser. Final stages of testing are being conducted to enable the FACStar Plus (and eventually the FACS Vantage) to perform analysis and sorting based upon 5 colors. This requires the use of interlaser compensation, previously unavailable. The amount of usage by DIR labs has increased from 3658.9 total hours in FY '94 to 4236 hours in FY '95. The percentage time devoted to sorting is expected to increase with the availability of the FACS Vantage.